Efficient Coding Unit and Mode Decision Algorithm for HEVC Intra Prediction

High efficiency video coding (HEVC) is the state-of-the-art video coding standard and better than the previous video coding standard H.264/AVC on coding efficiency. Under the similar image quality, HEVC can reduce data amount in the bit-stream around 50% compared with H.264/AVC. In terms of intra coding, HEVC can reduce data amount around 36% on average with respect to that of H.264/AVC. The expense of these improvements is a significant increase in the computational complexity. To reduce the computational burden, we propose an efficient intra coding algorithm based on edge information and spatial correlation for high efficiency video coding. We utilize the edge information applied in MPEG-7 and analyze the correlation of intra modes on the spatial domain to reduce the search numbers of Coding Unit(CU) and Prediction Unit(PU). In addition, our algorithm uses the rate-distortion cost(RD-cost) correlation between the current CU and adjacent CUs to early terminate computation for CU partition. Experimental results show that our algorithm can save 31.66% total time on average in HEVC encoder and maintain great video quality and similar bit-rate compared to HM11.0, and perform better than previous work.